public List<DoubleList<Split, Integer>> findConflictingSplitCounts(
     int threshold, boolean thresholdIsLength) {
   findGreedySplits();
   List<DoubleList<Split, Integer>> results =
       new Vector<DoubleList<Split, Integer>>(greedySplits.size());
   // could be more efficient by storing where the greedy splits appear in the sorted list.
   for (int i : greedySplitIndex) {
     String splitStr = sortedSplits.elementAt(i);
     Split split = splits.get(splitStr);
     if (!thresholdIsLength && counts.get(splitStr) < threshold)
       break; // ignore splits with frequency below threshold
     DoubleList<Split, Integer> splitList = new DoubleList<Split, Integer>();
     splitList.add(split, counts.get(splitStr));
     // Only check splits after this one in sorted list: ones before this one are guaranteed to be
     // compatible, else this split would not be in the greedy list.
     for (int j = i + 1; j < sortedSplits.size(); j++) {
       String otherSplitString = sortedSplits.elementAt(j);
       if (!thresholdIsLength && counts.get(otherSplitString) < threshold)
         break; // ignore conflicting splits with frequency below threshold
       Split otherSplit = splits.get(otherSplitString);
       if (!split.compatible(otherSplit)) {
         splitList.add(otherSplit, counts.get(otherSplitString));
       } // if !compatible
       if (thresholdIsLength && splitList.size() == threshold)
         break; // have enough secondary splits now
     } // for otherSplit (j)
     results.add(splitList);
   } // for i over sortedSplits
   return results;
 }
 /*
  * Does not recalculate if greedySplits are already cached.
  */
 private void findGreedySplits() {
   if (greedySplits != null) return;
   sortSplits();
   int nGreedySplits = idg.getIdCount() - 3;
   greedySplits = new Vector<Split>(nGreedySplits);
   greedySplitIndex = new Vector<Integer>(nGreedySplits);
   for (int i = 0; i < sortedSplits.size() && greedySplits.size() < nGreedySplits; i++) {
     String splitStr = sortedSplits.elementAt(i);
     Split split = splits.get(splitStr);
     if (split.compatible(greedySplits)) {
       greedySplits.add(split);
       greedySplitIndex.add(i);
     }
   }
 }